This disclosure relates to devices, methods and assemblies for determining landing of logging tools in a well.
In oil and gas exploration it is important to obtain diagnostic evaluation logs of geological formations penetrated by a wellbore from a subterranean reservoir. Diagnostic evaluation well logs are generated by data obtained by diagnostic tools (referred to in the industry as logging tools) that are lowered into the wellbore and passed across geologic formations that may contain hydrocarbon substances. Examples of well logs and logging tools are known in the art. Examples of diagnostic well logs include Neutron logs, Gamma Ray logs, Resistivity logs and Acoustic logs. Logging tools are frequently used for log data acquisition in a wellbore by logging in an upward (up hole) direction, such as from a bottom portion of the wellbore to an upper portion of the wellbore. The logging tools, therefore, need first be conveyed to the bottom portion of the wellbore. The landing position of the logging tools relative to the drill pipe (e.g., being at the end of the drill pipe) is important information for determining when to initiate data logging sequences and other aspects of logging tool operations. For example, logging tools may be in an inactive (e.g., sleep-mode) before landing at the end of the drill pipe for conserving onboard energy, reducing recording memory waste or unwanted data logs, and avoiding other potential interference incidents.